The objective of the proposed research is to develop and perfect a technique or surgical removal of diseased vitreous (vitrectomy through the pars plana with the vitreous infusion suction cutter (VISC). This involves the technical development of the VISC, the improvement of available operating microscopes, the development of surgical technique, the pre- and postoperative evaluation of patients who have undergone vitrectomy. BIBLIOGRAPHIC REFERENCES: Laqua, H. and Machemer, R.: Clinical-pathological correlation in massive periretinal proliferation. Am. J. Ophthal. 80:913-929, 1975. Laqua, H. and Machemer, R.: Glial cell proliferation in retinal detachment (massive periretinal proliferation). Am. J. Ophthal. 80:602-618, 1975.